you can manually edit forum/subscriptions/paypal.php, at about line 103 find:
PHP Code:
// Check if its a payment or if its a reversal
if ($_POST['txn_type'] == 'web_accept' AND $_POST['payment_status'] == 'Completed' OR $_POST['txn_type'] == 'subscr_payment' AND $_POST['payment_status'] == 'Completed')
{
if ($_POST['mc_gross'] == $cost[strtolower($_POST['mc_currency'])])
{
build_user_subscription($subscriptionid, $userid['userid']);
add after your desire function();
Just a few sql update statements